backport fixes to releases-v2 (#2526)

* backport fixes to releases-v2

* fix dist/index.js

.eslintrc.json

@@ -1,6 +1,6 @@
 {
   "plugins": ["jest", "@typescript-eslint"],
-  "extends": ["plugin:github/es6"],
+  "extends": ["plugin:github/recommended"],
   "parser": "@typescript-eslint/parser",
   "parserOptions": {
     "ecmaVersion": 9,
@@ -16,13 +16,9 @@
     "@typescript-eslint/no-require-imports": "error",
     "@typescript-eslint/array-type": "error",
     "@typescript-eslint/await-thenable": "error",
-    "@typescript-eslint/ban-ts-ignore": "error",
     "camelcase": "off",
-    "@typescript-eslint/camelcase": "error",
-    "@typescript-eslint/class-name-casing": "error",
     "@typescript-eslint/explicit-function-return-type": ["error", {"allowExpressions": true}],
     "@typescript-eslint/func-call-spacing": ["error", "never"],
-    "@typescript-eslint/generic-type-naming": ["error", "^[A-Z][A-Za-z]*$"],
     "@typescript-eslint/no-array-constructor": "error",
     "@typescript-eslint/no-empty-interface": "error",
     "@typescript-eslint/no-explicit-any": "error",
@@ -33,7 +29,6 @@
     "@typescript-eslint/no-misused-new": "error",
     "@typescript-eslint/no-namespace": "error",
     "@typescript-eslint/no-non-null-assertion": "warn",
-    "@typescript-eslint/no-object-literal-type-assertion": "error",
     "@typescript-eslint/no-unnecessary-qualifier": "error",
     "@typescript-eslint/no-unnecessary-type-assertion": "error",
     "@typescript-eslint/no-useless-constructor": "error",
@@ -41,7 +36,6 @@
     "@typescript-eslint/prefer-for-of": "warn",
     "@typescript-eslint/prefer-function-type": "warn",
     "@typescript-eslint/prefer-includes": "error",
-    "@typescript-eslint/prefer-interface": "error",
     "@typescript-eslint/prefer-string-starts-ends-with": "error",
     "@typescript-eslint/promise-function-async": "error",
     "@typescript-eslint/require-array-sort-compare": "error",

.github/workflows/check-dist.yml

@@ -0,0 +1,51 @@
+# `dist/index.js` is a special file in Actions.
+# When you reference an action with `uses:` in a workflow,
+# `index.js` is the code that will run.
+# For our project, we generate this file through a build process
+# from other source files.
+# We need to make sure the checked-in `index.js` actually matches what we expect it to be.
+name: Check dist
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - '**.md'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+  workflow_dispatch:
+
+jobs:
+  check-dist:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set Node.js 12.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Rebuild the index.js file
+        run: npm run build
+
+      - name: Compare the expected and actual dist/ directories
+        run: |
+          if [ "$(git diff --ignore-space-at-eol dist/ | wc -l)" -gt "0" ]; then
+            echo "Detected uncommitted changes after build.  See status below:"
+            git diff
+            exit 1
+          fi
+
+      # If dist/ was different than expected, upload the expected version as an artifact
+      - uses: actions/upload-artifact@v4
+        if: ${{ failure() && steps.diff.conclusion == 'failure' }}
+        with:
+          name: dist
+          path: dist/

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,58 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ main ]
+  schedule:
+    - cron: '28 9 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'javascript' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    - run: npm ci
+    - run: npm run build
+    - run: rm -rf dist # We want code scanning to analyze lib instead (individual .js files)
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/licensed.yml

@@ -11,10 +11,4 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - run: npm ci
-      - name: Install licensed
-        run: |
-          cd $RUNNER_TEMP
-          curl -Lfs -o licensed.tar.gz https://github.com/github/licensed/releases/download/2.12.2/licensed-2.12.2-linux-x64.tar.gz
-          sudo tar -xzf licensed.tar.gz
-          sudo mv licensed /usr/local/bin/licensed
-      - run: licensed status
+      - run: npm run licensed-check

.github/workflows/test.yml

@@ -142,7 +142,7 @@ jobs:
       options: --dns 127.0.0.1
     services:
       squid-proxy:
-        image: datadog/squid:latest
+        image: ubuntu/squid:latest
         ports:
           - 3128:3128
     env:
@@ -205,3 +205,41 @@ jobs:
           path: basic
       - name: Verify basic
         run: __test__/verify-basic.sh --archive
+    
+  test-git-container:
+    runs-on: ubuntu-latest
+    container: bitnami/git:latest
+    steps:
+      # Clone this repo
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          path: v3
+
+      # Basic checkout using git
+      - name: Checkout basic
+        uses: ./v3
+        with:
+          ref: test-data/v2/basic
+      - name: Verify basic
+        run: |
+          if [ ! -f "./basic-file.txt" ]; then
+              echo "Expected basic file does not exist"
+              exit 1
+          fi
+
+          # Verify .git folder
+          if [ ! -d "./.git" ]; then
+            echo "Expected ./.git folder to exist"
+            exit 1
+          fi
+
+          # Verify auth token
+          git config --global --add safe.directory "*"
+          git fetch --no-tags --depth=1 origin +refs/heads/main:refs/remotes/origin/main
+
+      # needed to make checkout post cleanup succeed
+      - name: Fix Checkout v3
+        uses: actions/checkout@v3
+        with:
+          path: v3

.gitignore

@@ -1,3 +1,4 @@
 __test__/_temp
+_temp/
 lib/
 node_modules/

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## v2.5.0
+- [Bump @actions/core to v1.10.0](https://github.com/actions/checkout/pull/962)
+
+## v2.4.2
+- [Add input `set-safe-directory`](https://github.com/actions/checkout/pull/776)
+
+## v2.4.1
+- [Set the safe directory option on git to prevent git commands failing when running in containers](https://github.com/actions/checkout/pull/762)
+
 ## v2.3.1
 
 - [Fix default branch resolution for .wiki and when using SSH](https://github.com/actions/checkout/pull/284)

README.md

@@ -105,6 +105,20 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
     #
     # Default: false
     submodules: ''
+
+    # Add repository path as safe.directory for Git global config by running `git
+    # config --global --add safe.directory <path>`
+    # Default: true
+    set-safe-directory: ''
+
+    # Required to check out fork pull request code from a workflow triggered by
+    # `pull_request_target` or `workflow_run`. These workflows run with the base
+    # repository's GITHUB_TOKEN, secrets, default-branch cache scope, and runner
+    # access; fetching and executing a fork's code in that trusted context commonly
+    # leads to "pwn request" vulnerabilities. Set to `true` only after reviewing the
+    # risks at https://gh.io/securely-using-pull_request_target.
+    # Default: false
+    allow-unsafe-pr-checkout: ''
 ```
 <!-- end usage -->
 
@@ -185,7 +199,7 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
   uses: actions/checkout@v2
   with:
     repository: my-org/my-private-tools
-    token: ${{ secrets.GitHub_PAT }} # `GitHub_PAT` is a secret that contains your PAT
+    token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
     path: my-tools
 ```
 

__test__/git-auth-helper.test.ts

@@ -417,7 +417,7 @@ describe('git-auth-helper tests', () => {
           `Did not expect file to exist: '${globalGitConfigPath}'`
         )
       } catch (err) {
-        if (err.code !== 'ENOENT') {
+        if ((err as any)?.code !== 'ENOENT') {
           throw err
         }
       }
@@ -518,12 +518,17 @@ describe('git-auth-helper tests', () => {
       await authHelper.configureSubmoduleAuth()
 
       // Assert
-      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(3)
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(4)
       expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
         /unset-all.*insteadOf/
       )
       expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/http.*extraheader/)
-      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(/url.*insteadOf/)
+      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(
+        /url.*insteadOf.*git@github.com:/
+      )
+      expect(mockSubmoduleForeach.mock.calls[3][0]).toMatch(
+        /url.*insteadOf.*org-123456@github.com:/
+      )
     }
   )
 
@@ -601,7 +606,7 @@ describe('git-auth-helper tests', () => {
       await fs.promises.stat(actualKeyPath)
       throw new Error('SSH key should have been deleted')
     } catch (err) {
-      if (err.code !== 'ENOENT') {
+      if ((err as any)?.code !== 'ENOENT') {
         throw err
       }
     }
@@ -611,7 +616,7 @@ describe('git-auth-helper tests', () => {
       await fs.promises.stat(actualKnownHostsPath)
       throw new Error('SSH known hosts should have been deleted')
     } catch (err) {
-      if (err.code !== 'ENOENT') {
+      if ((err as any)?.code !== 'ENOENT') {
         throw err
       }
     }
@@ -638,10 +643,11 @@ describe('git-auth-helper tests', () => {
     expect(gitConfigContent.indexOf('http.')).toBeLessThan(0)
   })
 
-  const removeGlobalAuth_removesOverride = 'removeGlobalAuth removes override'
-  it(removeGlobalAuth_removesOverride, async () => {
+  const removeGlobalConfig_removesOverride =
+    'removeGlobalConfig removes override'
+  it(removeGlobalConfig_removesOverride, async () => {
     // Arrange
-    await setup(removeGlobalAuth_removesOverride)
+    await setup(removeGlobalConfig_removesOverride)
     const authHelper = gitAuthHelper.createAuthHelper(git, settings)
     await authHelper.configureAuth()
     await authHelper.configureGlobalAuth()
@@ -650,7 +656,7 @@ describe('git-auth-helper tests', () => {
     await fs.promises.stat(path.join(git.env['HOME'], '.gitconfig'))
 
     // Act
-    await authHelper.removeGlobalAuth()
+    await authHelper.removeGlobalConfig()
 
     // Assert
     expect(git.env['HOME']).toBeUndefined()
@@ -658,7 +664,7 @@ describe('git-auth-helper tests', () => {
       await fs.promises.stat(homeOverride)
       throw new Error(`Should have been deleted '${homeOverride}'`)
     } catch (err) {
-      if (err.code !== 'ENOENT') {
+      if ((err as any)?.code !== 'ENOENT') {
         throw err
       }
     }
@@ -770,7 +776,10 @@ async function setup(testName: string): Promise<void> {
     repositoryPath: '',
     sshKey: sshPath ? 'some ssh private key' : '',
     sshKnownHosts: '',
-    sshStrict: true
+    sshStrict: true,
+    workflowOrganizationId: 123456,
+    setSafeDirectory: true,
+    allowUnsafePrCheckout: false
   }
 }
 

__test__/input-helper.test.ts

@@ -1,9 +1,9 @@
-import * as assert from 'assert'
 import * as core from '@actions/core'
 import * as fsHelper from '../lib/fs-helper'
 import * as github from '@actions/github'
 import * as inputHelper from '../lib/input-helper'
 import * as path from 'path'
+import * as workflowContextHelper from '../lib/workflow-context-helper'
 import {IGitSourceSettings} from '../lib/git-source-settings'
 
 const originalGitHubWorkspace = process.env['GITHUB_WORKSPACE']
@@ -12,15 +12,24 @@ const gitHubWorkspace = path.resolve('/checkout-tests/workspace')
 // Inputs for mock @actions/core
 let inputs = {} as any
 
+// Replicate @actions/core getInput behavior: it trims whitespace by default
+// (String.prototype.trim(), which strips characters such as a leading U+FEFF BOM)
+// unless trimWhitespace is explicitly set to false.
+const getInputImpl = (name: string, options?: {trimWhitespace?: boolean}) => {
+  const val = inputs[name] ?? ''
+  if (options && options.trimWhitespace === false) {
+    return val
+  }
+  return typeof val === 'string' ? val.trim() : val
+}
+
 // Shallow clone original @actions/github context
 let originalContext = {...github.context}
 
 describe('input-helper tests', () => {
   beforeAll(() => {
     // Mock getInput
-    jest.spyOn(core, 'getInput').mockImplementation((name: string) => {
-      return inputs[name]
-    })
+    jest.spyOn(core, 'getInput').mockImplementation(getInputImpl as any)
 
     // Mock error/warning/info/debug
     jest.spyOn(core, 'error').mockImplementation(jest.fn())
@@ -43,6 +52,11 @@ describe('input-helper tests', () => {
       .spyOn(fsHelper, 'directoryExistsSync')
       .mockImplementation((path: string) => path == gitHubWorkspace)
 
+    // Mock ./workflowContextHelper getOrganizationId()
+    jest
+      .spyOn(workflowContextHelper, 'getOrganizationId')
+      .mockImplementation(() => Promise.resolve(123456))
+
     // GitHub workspace
     process.env['GITHUB_WORKSPACE'] = gitHubWorkspace
   })
@@ -67,8 +81,8 @@ describe('input-helper tests', () => {
     jest.restoreAllMocks()
   })
 
-  it('sets defaults', () => {
-    const settings: IGitSourceSettings = inputHelper.getInputs()
+  it('sets defaults', async () => {
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings).toBeTruthy()
     expect(settings.authToken).toBeFalsy()
     expect(settings.clean).toBe(true)
@@ -80,13 +94,15 @@ describe('input-helper tests', () => {
     expect(settings.repositoryName).toBe('some-repo')
     expect(settings.repositoryOwner).toBe('some-owner')
     expect(settings.repositoryPath).toBe(gitHubWorkspace)
+    expect(settings.setSafeDirectory).toBe(true)
+    expect(settings.allowUnsafePrCheckout).toBe(false)
   })
 
-  it('qualifies ref', () => {
+  it('qualifies ref', async () => {
     let originalRef = github.context.ref
     try {
       github.context.ref = 'some-unqualified-ref'
-      const settings: IGitSourceSettings = inputHelper.getInputs()
+      const settings: IGitSourceSettings = await inputHelper.getInputs()
       expect(settings).toBeTruthy()
       expect(settings.commit).toBe('1234567890123456789012345678901234567890')
       expect(settings.ref).toBe('refs/heads/some-unqualified-ref')
@@ -95,32 +111,110 @@ describe('input-helper tests', () => {
     }
   })
 
-  it('requires qualified repo', () => {
+  it('requires qualified repo', async () => {
     inputs.repository = 'some-unqualified-repo'
-    assert.throws(() => {
-      inputHelper.getInputs()
-    }, /Invalid repository 'some-unqualified-repo'/)
+    try {
+      await inputHelper.getInputs()
+      throw 'should not reach here'
+    } catch (err) {
+      expect(`(${(err as any).message}`).toMatch(
+        "Invalid repository 'some-unqualified-repo'"
+      )
+    }
   })
 
-  it('roots path', () => {
+  it('roots path', async () => {
     inputs.path = 'some-directory/some-subdirectory'
-    const settings: IGitSourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.repositoryPath).toBe(
       path.join(gitHubWorkspace, 'some-directory', 'some-subdirectory')
     )
   })
 
-  it('sets ref to empty when explicit sha', () => {
+  it('sets ref to empty when explicit sha', async () => {
     inputs.ref = '1111111111222222222233333333334444444444'
-    const settings: IGitSourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.ref).toBeFalsy()
     expect(settings.commit).toBe('1111111111222222222233333333334444444444')
   })
 
-  it('sets sha to empty when explicit ref', () => {
+  it('sets sha to empty when explicit ref', async () => {
     inputs.ref = 'refs/heads/some-other-ref'
-    const settings: IGitSourceSettings = inputHelper.getInputs()
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
     expect(settings.ref).toBe('refs/heads/some-other-ref')
     expect(settings.commit).toBeFalsy()
   })
+
+  it('does not reclassify a ref as sha when a BOM is prefixed', async () => {
+    // A fork branch named "<U+FEFF>" + 40 hex chars. core.getInput trims the
+    // BOM by default, which previously collapsed this into a bare SHA and
+    // bypassed the unsafe fork PR checkout guard.
+    inputs.ref = '\uFEFF522d932fae5296da51fdf431934425ecf891c6a2'
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.commit).toBeFalsy()
+    expect(settings.ref).toBe('522d932fae5296da51fdf431934425ecf891c6a2')
+  })
+
+  it('treats a sha surrounded by ascii whitespace as a commit', async () => {
+    // ASCII whitespace can only come from the workflow author's YAML (git ref
+    // names cannot contain it), so trimming it and treating the value as a
+    // commit is safe.
+    inputs.ref = '  1111111111222222222233333333334444444444  '
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.ref).toBeFalsy()
+    expect(settings.commit).toBe('1111111111222222222233333333334444444444')
+  })
+
+  it('sets workflow organization ID', async () => {
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.workflowOrganizationId).toBe(123456)
+  })
+
+  describe('unsafe PR checkout guard', () => {
+    const forkPayload = {
+      repository: {id: 100},
+      pull_request: {
+        head: {
+          sha: '1234567890123456789012345678901234567890',
+          repo: {id: 200, full_name: 'attacker/fork'}
+        },
+        merge_commit_sha: 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
+      }
+    }
+
+    it('allows the default self-checkout on a fork pull_request_target', async () => {
+      const originalEvent = github.context.eventName
+      const originalPayload = github.context.payload
+      const originalSha = github.context.sha
+      try {
+        github.context.eventName = 'pull_request_target'
+        github.context.payload = forkPayload as any
+        // Simulate a rebase/fast-forward merge where the base tip (event SHA)
+        // equals the PR head SHA. The default self-checkout must still succeed.
+        github.context.sha = '1234567890123456789012345678901234567890'
+        const settings: IGitSourceSettings = await inputHelper.getInputs()
+        expect(settings.commit).toBe('1234567890123456789012345678901234567890')
+      } finally {
+        github.context.eventName = originalEvent
+        github.context.payload = originalPayload
+        github.context.sha = originalSha
+      }
+    })
+
+    it('refuses an explicit fork repository on pull_request_target', async () => {
+      const originalEvent = github.context.eventName
+      const originalPayload = github.context.payload
+      try {
+        github.context.eventName = 'pull_request_target'
+        github.context.payload = forkPayload as any
+        inputs.repository = 'attacker/fork'
+        await expect(inputHelper.getInputs()).rejects.toThrow(
+          /Refusing to check out fork pull request code/
+        )
+      } finally {
+        github.context.eventName = originalEvent
+        github.context.payload = originalPayload
+      }
+    })
+  })
 })

__test__/ref-helper.test.ts

@@ -16,7 +16,7 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, 'refs/heads/my/branch', commit)
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe('Arg git cannot be empty')
+      expect((err as any)?.message).toBe('Arg git cannot be empty')
     }
   })
 
@@ -25,7 +25,9 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, '', '')
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe('Args ref and commit cannot both be empty')
+      expect((err as any)?.message).toBe(
+        'Args ref and commit cannot both be empty'
+      )
     }
   })
 
@@ -102,7 +104,7 @@ describe('ref-helper tests', () => {
       await refHelper.getCheckoutInfo(git, 'my-ref', '')
       throw new Error('Should not reach here')
     } catch (err) {
-      expect(err.message).toBe(
+      expect((err as any)?.message).toBe(
         "A branch or tag with the name 'my-ref' could not be found"
       )
     }

__test__/retry-helper.test.ts

@@ -74,7 +74,7 @@ describe('retry-helper tests', () => {
         throw new Error(`some error ${++attempts}`)
       })
     } catch (err) {
-      error = err
+      error = err as Error
     }
     expect(error.message).toBe('some error 3')
     expect(attempts).toBe(3)

__test__/unsafe-pr-checkout-helper.test.ts

@@ -0,0 +1,267 @@
+import * as github from '@actions/github'
+import {assertSafePrCheckout} from '../lib/unsafe-pr-checkout-helper'
+
+// Shallow clone original @actions/github context
+const originalContext = {...github.context}
+const originalEventName = github.context.eventName
+const originalPayload = github.context.payload
+
+const BASE_REPO_ID = 100
+const FORK_REPO_ID = 200
+const PR_HEAD_SHA = '1111111111111111111111111111111111111111'
+const PR_MERGE_SHA = '2222222222222222222222222222222222222222'
+const SAFE_BASE_SHA = '3333333333333333333333333333333333333333'
+const WORKFLOW_RUN_HEAD_COMMIT_SHA = '4444444444444444444444444444444444444444'
+const BASE_QUALIFIED_REPO = 'some-owner/some-repo'
+const FORK_QUALIFIED_REPO = 'another-repo/fork'
+
+function setContext(eventName: string, payload: object): void {
+  ;(github.context as {eventName: string}).eventName = eventName
+  ;(github.context as {payload: object}).payload = payload
+}
+
+function forkPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: FORK_REPO_ID, full_name: FORK_QUALIFIED_REPO}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function sameRepoPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: BASE_REPO_ID, full_name: BASE_QUALIFIED_REPO}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function forkWorkflowRunPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    workflow_run: {
+      event: 'pull_request',
+      head_commit: {id: WORKFLOW_RUN_HEAD_COMMIT_SHA},
+      head_repository: {id: FORK_REPO_ID, full_name: FORK_QUALIFIED_REPO}
+    }
+  }
+}
+
+describe('unsafe-pr-checkout-helper', () => {
+  beforeAll(() => {
+    jest.spyOn(github.context, 'repo', 'get').mockReturnValue({
+      owner: 'some-owner',
+      repo: 'some-repo'
+    })
+  })
+
+  afterEach(() => {
+    ;(github.context as {eventName: string}).eventName = originalEventName
+    ;(github.context as {payload: object}).payload = originalPayload
+  })
+
+  afterAll(() => {
+    ;(github.context as {eventName: string}).eventName =
+      originalContext.eventName
+    ;(github.context as {payload: object}).payload = originalContext.payload
+    jest.restoreAllMocks()
+  })
+
+  it('allows pull_request events untouched', () => {
+    setContext('pull_request', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'attacker/fork',
+        ref: 'refs/pull/1/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows pull_request_target default checkout (base branch)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/heads/main',
+        commit: SAFE_BASE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows same-repo pull_request_target checkout of PR head', () => {
+    setContext('pull_request_target', sameRepoPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses pull_request_target fork PR head SHA checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/Refusing to check out fork pull request code/)
+  })
+
+  it('refuses pull_request_target fork PR merge_commit_sha checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_MERGE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/allow-unsafe-pr-checkout/)
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (head)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/head',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (merge)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target when repository points at the fork', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: FORK_QUALIFIED_REPO,
+        ref: 'refs/heads/main',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows pull_request_target checkout of an unrelated third-party repo', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'some-other/unrelated',
+        ref: 'refs/heads/main',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses pull_request_target ignoring repository case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: FORK_QUALIFIED_REPO.toUpperCase(),
+        ref: '',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target ignoring commit SHA case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA.toUpperCase(),
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows pull_request_target fork PR checkout when opted in', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: true
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses workflow_run fork PR head_commit.id checkout', () => {
+    setContext('workflow_run', forkWorkflowRunPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses workflow_run with pull_request_target underlying event', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {event: string}
+    }
+    payload.workflow_run.event = 'pull_request_target'
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows workflow_run same-repo PR (head_repository.id matches base)', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {head_repository: {id: number}}
+    }
+    payload.workflow_run.head_repository.id = BASE_REPO_ID
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+})

action.yml

@@ -68,6 +68,18 @@ inputs:
       When the `ssh-key` input is not provided, SSH URLs beginning with `git@github.com:` are
       converted to HTTPS.
     default: false
+  set-safe-directory:
+    description: Add repository path as safe.directory for Git global config by running `git config --global --add safe.directory <path>`
+    default: true
+  allow-unsafe-pr-checkout:
+    description: >
+      Required to check out fork pull request code from a workflow triggered by
+      `pull_request_target` or `workflow_run`. These workflows run with the
+      base repository's GITHUB_TOKEN, secrets, default-branch cache scope, and
+      runner access; fetching and executing a fork's code in that trusted
+      context commonly leads to "pwn request" vulnerabilities. Set to `true`
+      only after reviewing the risks at https://gh.io/securely-using-pull_request_target.
+    default: false
 runs:
   using: node12
   main: dist/index.js

package.json

@@ -1,6 +1,6 @@
 {
   "name": "checkout",
-  "version": "2.0.2",
+  "version": "2.6.0",
   "description": "checkout action",
   "main": "lib/main.js",
   "scripts": {
@@ -8,7 +8,9 @@
     "format": "prettier --write '**/*.ts'",
     "format-check": "prettier --check '**/*.ts'",
     "lint": "eslint src/**/*.ts",
-    "test": "jest"
+    "test": "jest",
+    "licensed-check": "src/misc/licensed-check.sh",
+    "licensed-generate": "src/misc/licensed-generate.sh"
   },
   "repository": {
     "type": "git",
@@ -26,27 +28,28 @@
   },
   "homepage": "https://github.com/actions/checkout#readme",
   "dependencies": {
-    "@actions/core": "^1.1.3",
+    "@actions/core": "^1.10.0",
     "@actions/exec": "^1.0.1",
     "@actions/github": "^2.2.0",
-    "@actions/io": "^1.0.1",
+    "@actions/io": "^1.1.2",
     "@actions/tool-cache": "^1.1.2",
     "uuid": "^3.3.3"
   },
   "devDependencies": {
-    "@types/jest": "^24.0.23",
+    "@types/jest": "^27.0.2",
     "@types/node": "^12.7.12",
     "@types/uuid": "^3.4.6",
-    "@typescript-eslint/parser": "^2.8.0",
+    "@typescript-eslint/eslint-plugin": "^5.45.0",
+    "@typescript-eslint/parser": "^5.45.0",
     "@zeit/ncc": "^0.20.5",
-    "eslint": "^5.16.0",
-    "eslint-plugin-github": "^2.0.0",
-    "eslint-plugin-jest": "^22.21.0",
-    "jest": "^24.9.0",
-    "jest-circus": "^24.9.0",
+    "eslint": "^7.32.0",
+    "eslint-plugin-github": "^4.3.2",
+    "eslint-plugin-jest": "^25.7.0",
+    "jest": "^27.3.0",
+    "jest-circus": "^27.3.0",
     "js-yaml": "^3.13.1",
     "prettier": "^1.19.1",
-    "ts-jest": "^24.2.0",
-    "typescript": "^3.6.4"
+    "ts-jest": "^27.0.7",
+    "typescript": "^4.4.4"
   }
 }

src/fs-helper.ts

@@ -9,7 +9,7 @@ export function directoryExistsSync(path: string, required?: boolean): boolean {
   try {
     stats = fs.statSync(path)
   } catch (error) {
-    if (error.code === 'ENOENT') {
+    if ((error as any)?.code === 'ENOENT') {
       if (!required) {
         return false
       }
@@ -18,7 +18,8 @@ export function directoryExistsSync(path: string, required?: boolean): boolean {
     }
 
     throw new Error(
-      `Encountered an error when checking whether path '${path}' exists: ${error.message}`
+      `Encountered an error when checking whether path '${path}' exists: ${(error as any)
+        ?.message ?? error}`
     )
   }
 
@@ -39,12 +40,13 @@ export function existsSync(path: string): boolean {
   try {
     fs.statSync(path)
   } catch (error) {
-    if (error.code === 'ENOENT') {
+    if ((error as any)?.code === 'ENOENT') {
       return false
     }
 
     throw new Error(
-      `Encountered an error when checking whether path '${path}' exists: ${error.message}`
+      `Encountered an error when checking whether path '${path}' exists: ${(error as any)
+        ?.message ?? error}`
     )
   }
 
@@ -60,12 +62,13 @@ export function fileExistsSync(path: string): boolean {
   try {
     stats = fs.statSync(path)
   } catch (error) {
-    if (error.code === 'ENOENT') {
+    if ((error as any)?.code === 'ENOENT') {
       return false
     }
 
     throw new Error(
-      `Encountered an error when checking whether path '${path}' exists: ${error.message}`
+      `Encountered an error when checking whether path '${path}' exists: ${(error as any)
+        ?.message ?? error}`
     )
   }
 

src/git-auth-helper.ts

@@ -19,8 +19,9 @@ export interface IGitAuthHelper {
   configureAuth(): Promise<void>
   configureGlobalAuth(): Promise<void>
   configureSubmoduleAuth(): Promise<void>
+  configureTempGlobalConfig(): Promise<string>
   removeAuth(): Promise<void>
-  removeGlobalAuth(): Promise<void>
+  removeGlobalConfig(): Promise<void>
 }
 
 export function createAuthHelper(
@@ -37,7 +38,7 @@ class GitAuthHelper {
   private readonly tokenConfigValue: string
   private readonly tokenPlaceholderConfigValue: string
   private readonly insteadOfKey: string
-  private readonly insteadOfValue: string
+  private readonly insteadOfValues: string[] = []
   private sshCommand = ''
   private sshKeyPath = ''
   private sshKnownHostsPath = ''
@@ -45,7 +46,7 @@ class GitAuthHelper {
 
   constructor(
     gitCommandManager: IGitCommandManager,
-    gitSourceSettings?: IGitSourceSettings
+    gitSourceSettings: IGitSourceSettings | undefined
   ) {
     this.git = gitCommandManager
     this.settings = gitSourceSettings || (({} as unknown) as IGitSourceSettings)
@@ -63,7 +64,12 @@ class GitAuthHelper {
 
     // Instead of SSH URL
     this.insteadOfKey = `url.${serverUrl.origin}/.insteadOf` // "origin" is SCHEME://HOSTNAME[:PORT]
-    this.insteadOfValue = `git@${serverUrl.hostname}:`
+    this.insteadOfValues.push(`git@${serverUrl.hostname}:`)
+    if (this.settings.workflowOrganizationId) {
+      this.insteadOfValues.push(
+        `org-${this.settings.workflowOrganizationId}@github.com:`
+      )
+    }
   }
 
   async configureAuth(): Promise<void> {
@@ -75,7 +81,11 @@ class GitAuthHelper {
     await this.configureToken()
   }
 
-  async configureGlobalAuth(): Promise<void> {
+  async configureTempGlobalConfig(): Promise<string> {
+    // Already setup global config
+    if (this.temporaryHomePath?.length > 0) {
+      return path.join(this.temporaryHomePath, '.gitconfig')
+    }
     // Create a temp home directory
     const runnerTemp = process.env['RUNNER_TEMP'] || ''
     assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
@@ -94,7 +104,7 @@ class GitAuthHelper {
       await fs.promises.stat(gitConfigPath)
       configExists = true
     } catch (err) {
-      if (err.code !== 'ENOENT') {
+      if ((err as any)?.code !== 'ENOENT') {
         throw err
       }
     }
@@ -105,20 +115,28 @@ class GitAuthHelper {
       await fs.promises.writeFile(newGitConfigPath, '')
     }
 
-    try {
-      // Override HOME
-      core.info(
-        `Temporarily overriding HOME='${this.temporaryHomePath}' before making global git config changes`
-      )
-      this.git.setEnvironmentVariable('HOME', this.temporaryHomePath)
+    // Override HOME
+    core.info(
+      `Temporarily overriding HOME='${this.temporaryHomePath}' before making global git config changes`
+    )
+    this.git.setEnvironmentVariable('HOME', this.temporaryHomePath)
 
+    return newGitConfigPath
+  }
+
+  async configureGlobalAuth(): Promise<void> {
+    // 'configureTempGlobalConfig' noops if already set, just returns the path
+    const newGitConfigPath = await this.configureTempGlobalConfig()
+    try {
       // Configure the token
       await this.configureToken(newGitConfigPath, true)
 
       // Configure HTTPS instead of SSH
       await this.git.tryConfigUnset(this.insteadOfKey, true)
       if (!this.settings.sshKey) {
-        await this.git.config(this.insteadOfKey, this.insteadOfValue, true)
+        for (const insteadOfValue of this.insteadOfValues) {
+          await this.git.config(this.insteadOfKey, insteadOfValue, true, true)
+        }
       }
     } catch (err) {
       // Unset in case somehow written to the real global config
@@ -139,7 +157,8 @@ class GitAuthHelper {
       // by process creation audit events, which are commonly logged. For more information,
       // refer to https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
       const output = await this.git.submoduleForeach(
-        `git config --local '${this.tokenConfigKey}' '${this.tokenPlaceholderConfigValue}' && git config --local --show-origin --name-only --get-regexp remote.origin.url`,
+        // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
+        `sh -c "git config --local '${this.tokenConfigKey}' '${this.tokenPlaceholderConfigValue}' && git config --local --show-origin --name-only --get-regexp remote.origin.url"`,
         this.settings.nestedSubmodules
       )
 
@@ -159,10 +178,12 @@ class GitAuthHelper {
         )
       } else {
         // Configure HTTPS instead of SSH
-        await this.git.submoduleForeach(
-          `git config --local '${this.insteadOfKey}' '${this.insteadOfValue}'`,
-          this.settings.nestedSubmodules
-        )
+        for (const insteadOfValue of this.insteadOfValues) {
+          await this.git.submoduleForeach(
+            `git config --local --add '${this.insteadOfKey}' '${insteadOfValue}'`,
+            this.settings.nestedSubmodules
+          )
+        }
       }
     }
   }
@@ -172,10 +193,12 @@ class GitAuthHelper {
     await this.removeToken()
   }
 
-  async removeGlobalAuth(): Promise<void> {
-    core.debug(`Unsetting HOME override`)
-    this.git.removeEnvironmentVariable('HOME')
-    await io.rmRF(this.temporaryHomePath)
+  async removeGlobalConfig(): Promise<void> {
+    if (this.temporaryHomePath?.length > 0) {
+      core.debug(`Unsetting HOME override`)
+      this.git.removeEnvironmentVariable('HOME')
+      await io.rmRF(this.temporaryHomePath)
+    }
   }
 
   private async configureSsh(): Promise<void> {
@@ -213,7 +236,7 @@ class GitAuthHelper {
         await fs.promises.readFile(userKnownHostsPath)
       ).toString()
     } catch (err) {
-      if (err.code !== 'ENOENT') {
+      if ((err as any)?.code !== 'ENOENT') {
         throw err
       }
     }
@@ -224,7 +247,7 @@ class GitAuthHelper {
     if (this.settings.sshKnownHosts) {
       knownHosts += `# Begin from input known hosts\n${this.settings.sshKnownHosts}\n# end from input known hosts\n`
     }
-    knownHosts += `# Begin implicitly added github.com\ngithub.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==\n# End implicitly added github.com\n`
+    knownHosts += `# Begin implicitly added github.com\ngithub.com ssh-rsa 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\n# End implicitly added github.com\n`
     this.sshKnownHostsPath = path.join(runnerTemp, `${uniqueId}_known_hosts`)
     stateHelper.setSshKnownHostsPath(this.sshKnownHostsPath)
     await fs.promises.writeFile(this.sshKnownHostsPath, knownHosts)
@@ -302,7 +325,7 @@ class GitAuthHelper {
       try {
         await io.rmRF(keyPath)
       } catch (err) {
-        core.debug(err.message)
+        core.debug(`${(err as any)?.message ?? err}`)
         core.warning(`Failed to remove SSH key '${keyPath}'`)
       }
     }
@@ -343,7 +366,8 @@ class GitAuthHelper {
 
     const pattern = regexpHelper.escape(configKey)
     await this.git.submoduleForeach(
-      `git config --local --name-only --get-regexp '${pattern}' && git config --local --unset-all '${configKey}' || :`,
+      // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
+      `sh -c "git config --local --name-only --get-regexp '${pattern}' && git config --local --unset-all '${configKey}' || :"`,
       true
     )
   }

src/git-command-manager.ts

@@ -21,7 +21,8 @@ export interface IGitCommandManager {
   config(
     configKey: string,
     configValue: string,
-    globalConfig?: boolean
+    globalConfig?: boolean,
+    add?: boolean
   ): Promise<void>
   configExists(configKey: string, globalConfig?: boolean): Promise<boolean>
   fetch(refSpec: string[], fetchDepth?: number): Promise<void>
@@ -140,14 +141,15 @@ class GitCommandManager {
   async config(
     configKey: string,
     configValue: string,
-    globalConfig?: boolean
+    globalConfig?: boolean,
+    add?: boolean
   ): Promise<void> {
-    await this.execGit([
-      'config',
-      globalConfig ? '--global' : '--local',
-      configKey,
-      configValue
-    ])
+    const args: string[] = ['config', globalConfig ? '--global' : '--local']
+    if (add) {
+      args.push('--add')
+    }
+    args.push(...[configKey, configValue])
+    await this.execGit(args)
   }
 
   async configExists(

src/git-directory-helper.ts

@@ -39,7 +39,9 @@ export async function prepareExistingDirectory(
       try {
         await io.rmRF(lockPath)
       } catch (error) {
-        core.debug(`Unable to delete '${lockPath}'. ${error.message}`)
+        core.debug(
+          `Unable to delete '${lockPath}'. ${(error as any)?.message ?? error}`
+        )
       }
     }
 

src/git-source-provider.ts

@@ -36,68 +36,94 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
   const git = await getGitCommandManager(settings)
   core.endGroup()
 
-  // Prepare existing directory, otherwise recreate
-  if (isExisting) {
-    await gitDirectoryHelper.prepareExistingDirectory(
-      git,
-      settings.repositoryPath,
-      repositoryUrl,
-      settings.clean,
-      settings.ref
-    )
-  }
+  let authHelper: gitAuthHelper.IGitAuthHelper | null = null
+  try {
+    if (git) {
+      authHelper = gitAuthHelper.createAuthHelper(git, settings)
+      if (settings.setSafeDirectory) {
+        // Setup the repository path as a safe directory, so if we pass this into a container job with a different user it doesn't fail
+        // Otherwise all git commands we run in a container fail
+        await authHelper.configureTempGlobalConfig()
+        core.info(
+          `Adding repository directory to the temporary git global config as a safe directory`
+        )
 
-  if (!git) {
-    // Downloading using REST API
-    core.info(`The repository will be downloaded using the GitHub REST API`)
-    core.info(
-      `To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH`
-    )
-    if (settings.submodules) {
-      throw new Error(
-        `Input 'submodules' not supported when falling back to download using the GitHub REST API. To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH.`
-      )
-    } else if (settings.sshKey) {
-      throw new Error(
-        `Input 'ssh-key' not supported when falling back to download using the GitHub REST API. To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH.`
+        await git
+          .config('safe.directory', settings.repositoryPath, true, true)
+          .catch(error => {
+            core.info(
+              `Failed to initialize safe directory with error: ${error}`
+            )
+          })
+
+        stateHelper.setSafeDirectory()
+      }
+    }
+
+    // Prepare existing directory, otherwise recreate
+    if (isExisting) {
+      await gitDirectoryHelper.prepareExistingDirectory(
+        git,
+        settings.repositoryPath,
+        repositoryUrl,
+        settings.clean,
+        settings.ref
       )
     }
 
-    await githubApiHelper.downloadRepository(
-      settings.authToken,
-      settings.repositoryOwner,
-      settings.repositoryName,
-      settings.ref,
-      settings.commit,
-      settings.repositoryPath
-    )
-    return
-  }
+    if (!git) {
+      // Downloading using REST API
+      core.info(`The repository will be downloaded using the GitHub REST API`)
+      core.info(
+        `To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH`
+      )
+      if (settings.submodules) {
+        throw new Error(
+          `Input 'submodules' not supported when falling back to download using the GitHub REST API. To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH.`
+        )
+      } else if (settings.sshKey) {
+        throw new Error(
+          `Input 'ssh-key' not supported when falling back to download using the GitHub REST API. To create a local Git repository instead, add Git ${gitCommandManager.MinimumGitVersion} or higher to the PATH.`
+        )
+      }
 
-  // Save state for POST action
-  stateHelper.setRepositoryPath(settings.repositoryPath)
+      await githubApiHelper.downloadRepository(
+        settings.authToken,
+        settings.repositoryOwner,
+        settings.repositoryName,
+        settings.ref,
+        settings.commit,
+        settings.repositoryPath
+      )
+      return
+    }
 
-  // Initialize the repository
-  if (
-    !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
-  ) {
-    core.startGroup('Initializing the repository')
-    await git.init()
-    await git.remoteAdd('origin', repositoryUrl)
+    // Save state for POST action
+    stateHelper.setRepositoryPath(settings.repositoryPath)
+
+    // Initialize the repository
+    if (
+      !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
+    ) {
+      core.startGroup('Initializing the repository')
+      await git.init()
+      await git.remoteAdd('origin', repositoryUrl)
+      core.endGroup()
+    }
+
+    // Disable automatic garbage collection
+    core.startGroup('Disabling automatic garbage collection')
+    if (!(await git.tryDisableAutomaticGarbageCollection())) {
+      core.warning(
+        `Unable to turn off git automatic garbage collection. The git fetch operation may trigger garbage collection and cause a delay.`
+      )
+    }
     core.endGroup()
-  }
 
-  // Disable automatic garbage collection
-  core.startGroup('Disabling automatic garbage collection')
-  if (!(await git.tryDisableAutomaticGarbageCollection())) {
-    core.warning(
-      `Unable to turn off git automatic garbage collection. The git fetch operation may trigger garbage collection and cause a delay.`
-    )
-  }
-  core.endGroup()
-
-  const authHelper = gitAuthHelper.createAuthHelper(git, settings)
-  try {
+    // If we didn't initialize it above, do it now
+    if (!authHelper) {
+      authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    }
     // Configure auth
     core.startGroup('Setting up auth')
     await authHelper.configureAuth()
@@ -170,34 +196,26 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
 
     // Submodules
     if (settings.submodules) {
-      try {
-        // Temporarily override global config
-        core.startGroup('Setting up auth for fetching submodules')
-        await authHelper.configureGlobalAuth()
-        core.endGroup()
+      // Temporarily override global config
+      core.startGroup('Setting up auth for fetching submodules')
+      await authHelper.configureGlobalAuth()
+      core.endGroup()
 
-        // Checkout submodules
-        core.startGroup('Fetching submodules')
-        await git.submoduleSync(settings.nestedSubmodules)
-        await git.submoduleUpdate(
-          settings.fetchDepth,
-          settings.nestedSubmodules
-        )
-        await git.submoduleForeach(
-          'git config --local gc.auto 0',
-          settings.nestedSubmodules
-        )
-        core.endGroup()
+      // Checkout submodules
+      core.startGroup('Fetching submodules')
+      await git.submoduleSync(settings.nestedSubmodules)
+      await git.submoduleUpdate(settings.fetchDepth, settings.nestedSubmodules)
+      await git.submoduleForeach(
+        'git config --local gc.auto 0',
+        settings.nestedSubmodules
+      )
+      core.endGroup()
 
-        // Persist credentials
-        if (settings.persistCredentials) {
-          core.startGroup('Persisting credentials for submodules')
-          await authHelper.configureSubmoduleAuth()
-          core.endGroup()
-        }
-      } finally {
-        // Remove temporary global config override
-        await authHelper.removeGlobalAuth()
+      // Persist credentials
+      if (settings.persistCredentials) {
+        core.startGroup('Persisting credentials for submodules')
+        await authHelper.configureSubmoduleAuth()
+        core.endGroup()
       }
     }
 
@@ -218,10 +236,13 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
     )
   } finally {
     // Remove auth
-    if (!settings.persistCredentials) {
-      core.startGroup('Removing auth')
-      await authHelper.removeAuth()
-      core.endGroup()
+    if (authHelper) {
+      if (!settings.persistCredentials) {
+        core.startGroup('Removing auth')
+        await authHelper.removeAuth()
+        core.endGroup()
+      }
+      authHelper.removeGlobalConfig()
     }
   }
 }
@@ -244,7 +265,26 @@ export async function cleanup(repositoryPath: string): Promise<void> {
 
   // Remove auth
   const authHelper = gitAuthHelper.createAuthHelper(git)
-  await authHelper.removeAuth()
+  try {
+    if (stateHelper.PostSetSafeDirectory) {
+      // Setup the repository path as a safe directory, so if we pass this into a container job with a different user it doesn't fail
+      // Otherwise all git commands we run in a container fail
+      await authHelper.configureTempGlobalConfig()
+      core.info(
+        `Adding repository directory to the temporary git global config as a safe directory`
+      )
+
+      await git
+        .config('safe.directory', repositoryPath, true, true)
+        .catch(error => {
+          core.info(`Failed to initialize safe directory with error: ${error}`)
+        })
+    }
+
+    await authHelper.removeAuth()
+  } finally {
+    await authHelper.removeGlobalConfig()
+  }
 }
 
 async function getGitCommandManager(

src/git-source-settings.ts

@@ -73,4 +73,20 @@ export interface IGitSourceSettings {
    * Indicates whether to persist the credentials on disk to enable scripting authenticated git commands
    */
   persistCredentials: boolean
+
+  /**
+   * Organization ID for the currently running workflow (used for auth settings)
+   */
+  workflowOrganizationId: number | undefined
+
+  /**
+   * Indicates whether to add repositoryPath as safe.directory in git global config
+   */
+  setSafeDirectory: boolean
+
+  /**
+   * Opt-in to allow checking out fork pull request code from a workflow
+   * triggered by pull_request_target or workflow_run.
+   */
+  allowUnsafePrCheckout: boolean
 }

src/github-api-helper.ts

@@ -92,7 +92,10 @@ export async function getDefaultBranch(
       assert.ok(result, 'default_branch cannot be empty')
     } catch (err) {
       // Handle .wiki repo
-      if (err['status'] === 404 && repo.toUpperCase().endsWith('.WIKI')) {
+      if (
+        (err as any)?.status === 404 &&
+        repo.toUpperCase().endsWith('.WIKI')
+      ) {
         result = 'master'
       }
       // Otherwise error

src/input-helper.ts

@@ -2,9 +2,11 @@ import * as core from '@actions/core'
 import * as fsHelper from './fs-helper'
 import * as github from '@actions/github'
 import * as path from 'path'
+import * as unsafePrCheckoutHelper from './unsafe-pr-checkout-helper'
+import * as workflowContextHelper from './workflow-context-helper'
 import {IGitSourceSettings} from './git-source-settings'
 
-export function getInputs(): IGitSourceSettings {
+export async function getInputs(): Promise<IGitSourceSettings> {
   const result = ({} as unknown) as IGitSourceSettings
 
   // GitHub workspace
@@ -57,6 +59,23 @@ export function getInputs(): IGitSourceSettings {
 
   // Source branch, source version
   result.ref = core.getInput('ref')
+  // core.getInput()'s default trim strips a range of Unicode characters such as a
+  // leading BOM (U+FEFF) or NBSP (U+00A0). Those are valid in a git ref name, so
+  // a fork branch named "<BOM>" + 40 hex chars would trim down to a bare SHA and
+  // be silently reclassified as a commit, bypassing the unsafe fork PR checkout
+  // guard.
+  //
+  // The trim below strips only the ASCII whitespace characters which are all forbidden
+  // in a git branch name.
+  //   \t  U+0009  horizontal tab   - ASCII control, forbidden in ref names
+  //   \n  U+000A  line feed        - ASCII control, forbidden in ref names
+  //   \v  U+000B  vertical tab     - ASCII control, forbidden in ref names
+  //   \f  U+000C  form feed        - ASCII control, forbidden in ref names
+  //   \r  U+000D  carriage return  - ASCII control, forbidden in ref names
+  //   ' ' U+0020  space            - forbidden in ref names
+  const asciiTrimmedRef = core
+    .getInput('ref', {trimWhitespace: false})
+    .replace(/^[\t\n\v\f\r ]+|[\t\n\v\f\r ]+$/g, '')
   if (!result.ref) {
     if (isWorkflowRepository) {
       result.ref = github.context.ref
@@ -70,8 +89,8 @@ export function getInputs(): IGitSourceSettings {
     }
   }
   // SHA?
-  else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
-    result.commit = result.ref
+  else if (asciiTrimmedRef.match(/^[0-9a-fA-F]{40}$/)) {
+    result.commit = asciiTrimmedRef
     result.ref = ''
   }
   core.debug(`ref = '${result.ref}'`)
@@ -118,5 +137,32 @@ export function getInputs(): IGitSourceSettings {
   result.persistCredentials =
     (core.getInput('persist-credentials') || 'false').toUpperCase() === 'TRUE'
 
+  // Workflow organization ID
+  result.workflowOrganizationId = await workflowContextHelper.getOrganizationId()
+
+  // Set safe.directory in git global config.
+  result.setSafeDirectory =
+    (core.getInput('set-safe-directory') || 'true').toUpperCase() === 'TRUE'
+
+  // Allow unsafe PR checkout (opt-in for pull_request_target / workflow_run fork PRs)
+  result.allowUnsafePrCheckout =
+    (core.getInput('allow-unsafe-pr-checkout') || 'false').toUpperCase() ===
+    'TRUE'
+  core.debug(`allow unsafe PR checkout = ${result.allowUnsafePrCheckout}`)
+
+  // The default self-checkout (this repository with no explicit ref) always
+  // resolves to the trusted ref/commit GitHub set for the triggering event, so
+  // the fork-checkout guard only needs to run when the caller customized the
+  // repository or ref.
+  const isDefaultCheckout = isWorkflowRepository && !core.getInput('ref')
+  if (!isDefaultCheckout) {
+    unsafePrCheckoutHelper.assertSafePrCheckout({
+      qualifiedRepository,
+      ref: result.ref,
+      commit: result.commit,
+      allowUnsafePrCheckout: result.allowUnsafePrCheckout
+    })
+  }
+
   return result
 }

src/main.ts

@@ -7,7 +7,7 @@ import * as stateHelper from './state-helper'
 
 async function run(): Promise<void> {
   try {
-    const sourceSettings = inputHelper.getInputs()
+    const sourceSettings = await inputHelper.getInputs()
 
     try {
       // Register problem matcher
@@ -24,7 +24,7 @@ async function run(): Promise<void> {
       coreCommand.issueCommand('remove-matcher', {owner: 'checkout-git'}, '')
     }
   } catch (error) {
-    core.setFailed(error.message)
+    core.setFailed(`${(error as any)?.message ?? error}`)
   }
 }
 
@@ -32,7 +32,7 @@ async function cleanup(): Promise<void> {
   try {
     await gitSourceProvider.cleanup(stateHelper.RepositoryPath)
   } catch (error) {
-    core.warning(error.message)
+    core.warning(`${(error as any)?.message ?? error}`)
   }
 }
 

src/misc/generate-docs.ts

@@ -10,10 +10,10 @@ import * as yaml from 'js-yaml'
 
 function updateUsage(
   actionReference: string,
-  actionYamlPath: string = 'action.yml',
-  readmePath: string = 'README.md',
-  startToken: string = '<!-- start usage -->',
-  endToken: string = '<!-- end usage -->'
+  actionYamlPath = 'action.yml',
+  readmePath = 'README.md',
+  startToken = '<!-- start usage -->',
+  endToken = '<!-- end usage -->'
 ): void {
   if (!actionReference) {
     throw new Error('Parameter actionReference must not be empty')

src/misc/licensed-check.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+set -e
+
+src/misc/licensed-download.sh
+
+echo 'Running: licensed cached'
+_temp/licensed-3.6.0/licensed status

src/misc/licensed-download.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+set -e
+
+if [ ! -f _temp/licensed-3.6.0.done ]; then
+  echo 'Clearing temp'
+  rm -rf _temp/licensed-3.6.0 || true
+
+  echo 'Downloading licensed'
+  mkdir -p _temp/licensed-3.6.0
+  pushd _temp/licensed-3.6.0
+  if [[ "$OSTYPE" == "darwin"* ]]; then
+    curl -Lfs -o licensed.tar.gz https://github.com/github/licensed/releases/download/3.6.0/licensed-3.6.0-darwin-x64.tar.gz
+  else
+    curl -Lfs -o licensed.tar.gz https://github.com/github/licensed/releases/download/3.6.0/licensed-3.6.0-linux-x64.tar.gz
+  fi
+
+  echo 'Extracting licenesed'
+  tar -xzf licensed.tar.gz
+  popd
+  touch _temp/licensed-3.6.0.done
+else
+  echo 'Licensed already downloaded'
+fi

src/misc/licensed-generate.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+set -e
+
+src/misc/licensed-download.sh
+
+echo 'Running: licensed cached'
+_temp/licensed-3.6.0/licensed cache

src/ref-helper.ts

@@ -253,11 +253,13 @@ export async function checkCommitInfo(
       await octokit.repos.get({owner: repositoryOwner, repo: repositoryName})
     }
   } catch (err) {
-    core.debug(`Error when validating commit info: ${err.stack}`)
+    core.debug(
+      `Error when validating commit info: ${(err as any)?.stack ?? err}`
+    )
   }
 }
 
-function fromPayload(path: string): any {
+export function fromPayload(path: string): any {
   return select(github.context.payload, path)
 }
 

src/retry-helper.ts

@@ -29,7 +29,7 @@ export class RetryHelper {
       try {
         return await action()
       } catch (err) {
-        core.info(err.message)
+        core.info((err as any)?.message)
       }
 
       // Sleep

src/state-helper.ts

@@ -1,58 +1,60 @@
-import * as coreCommand from '@actions/core/lib/command'
+import * as core from '@actions/core'
 
 /**
  * Indicates whether the POST action is running
  */
-export const IsPost = !!process.env['STATE_isPost']
+export const IsPost = !!core.getState('isPost')
 
 /**
  * The repository path for the POST action. The value is empty during the MAIN action.
  */
-export const RepositoryPath =
-  (process.env['STATE_repositoryPath'] as string) || ''
+export const RepositoryPath = core.getState('repositoryPath')
+
+/**
+ * The set-safe-directory for the POST action. The value is set if input: 'safe-directory' is set during the MAIN action.
+ */
+export const PostSetSafeDirectory = core.getState('setSafeDirectory') === 'true'
 
 /**
  * The SSH key path for the POST action. The value is empty during the MAIN action.
  */
-export const SshKeyPath = (process.env['STATE_sshKeyPath'] as string) || ''
+export const SshKeyPath = core.getState('sshKeyPath')
 
 /**
  * The SSH known hosts path for the POST action. The value is empty during the MAIN action.
  */
-export const SshKnownHostsPath =
-  (process.env['STATE_sshKnownHostsPath'] as string) || ''
+export const SshKnownHostsPath = core.getState('sshKnownHostsPath')
 
 /**
  * Save the repository path so the POST action can retrieve the value.
  */
 export function setRepositoryPath(repositoryPath: string) {
-  coreCommand.issueCommand(
-    'save-state',
-    {name: 'repositoryPath'},
-    repositoryPath
-  )
+  core.saveState('repositoryPath', repositoryPath)
 }
 
 /**
  * Save the SSH key path so the POST action can retrieve the value.
  */
 export function setSshKeyPath(sshKeyPath: string) {
-  coreCommand.issueCommand('save-state', {name: 'sshKeyPath'}, sshKeyPath)
+  core.saveState('sshKeyPath', sshKeyPath)
 }
 
 /**
  * Save the SSH known hosts path so the POST action can retrieve the value.
  */
 export function setSshKnownHostsPath(sshKnownHostsPath: string) {
-  coreCommand.issueCommand(
-    'save-state',
-    {name: 'sshKnownHostsPath'},
-    sshKnownHostsPath
-  )
+  core.saveState('sshKnownHostsPath', sshKnownHostsPath)
+}
+
+/**
+ * Save the sef-safe-directory input so the POST action can retrieve the value.
+ */
+export function setSafeDirectory() {
+  core.saveState('setSafeDirectory', 'true')
 }
 
 // Publish a variable so that when the POST action runs, it can determine it should run the cleanup logic.
 // This is necessary since we don't have a separate entry point.
 if (!IsPost) {
-  coreCommand.issueCommand('save-state', {name: 'isPost'}, 'true')
+  core.saveState('isPost', 'true')
 }

src/unsafe-pr-checkout-helper.ts

@@ -0,0 +1,88 @@
+import * as github from '@actions/github'
+import {fromPayload} from './ref-helper'
+
+const PR_REF_PATTERN = /^refs\/pull\/[0-9]+\/(?:head|merge)$/
+
+export interface IUnsafePrCheckoutInput {
+  qualifiedRepository: string
+  ref: string
+  commit: string | undefined
+  allowUnsafePrCheckout: boolean
+}
+
+export function assertSafePrCheckout(input: IUnsafePrCheckoutInput): void {
+  if (input.allowUnsafePrCheckout) {
+    return
+  }
+
+  const eventName = github.context.eventName
+  if (eventName !== 'pull_request_target' && eventName !== 'workflow_run') {
+    return
+  }
+
+  const baseRepoId = fromPayload('repository.id')
+  if (typeof baseRepoId !== 'number') {
+    return
+  }
+
+  let prHeadRepoId: unknown
+  let prHeadRepoFullName: unknown
+  const prShas: string[] = []
+
+  if (eventName === 'pull_request_target') {
+    prHeadRepoId = fromPayload('pull_request.head.repo.id')
+    prHeadRepoFullName = fromPayload('pull_request.head.repo.full_name')
+    pushIfSha(prShas, fromPayload('pull_request.head.sha'))
+    pushIfSha(prShas, fromPayload('pull_request.merge_commit_sha'))
+  } else {
+    const wrEvent = fromPayload('workflow_run.event')
+    if (typeof wrEvent !== 'string' || !wrEvent.startsWith('pull_request')) {
+      return
+    }
+    prHeadRepoId = fromPayload('workflow_run.head_repository.id')
+    prHeadRepoFullName = fromPayload('workflow_run.head_repository.full_name')
+    pushIfSha(prShas, fromPayload('workflow_run.head_commit.id'))
+    // For `pull_request_target`-triggered workflow_run, `head_sha` is the base
+    // default branch SHA (not the PR head)
+    if (wrEvent !== 'pull_request_target') {
+      pushIfSha(prShas, fromPayload('workflow_run.head_sha'))
+    }
+  }
+
+  // (A) Fork PR?
+  if (typeof prHeadRepoId !== 'number' || prHeadRepoId === baseRepoId) {
+    return
+  }
+
+  // (B) We cannot check for all fork PR refs so check to see
+  // if the resolved input points to the fork PR sha we have in the payload
+  const repositoryMatchesPrHead =
+    typeof prHeadRepoFullName === 'string' &&
+    input.qualifiedRepository.toLowerCase() === prHeadRepoFullName.toLowerCase()
+  const refMatchesPullPattern = PR_REF_PATTERN.test(input.ref)
+  const commitMatchesPrHeadSha =
+    !!input.commit && prShas.includes(input.commit.toLowerCase())
+
+  if (
+    !repositoryMatchesPrHead &&
+    !refMatchesPullPattern &&
+    !commitMatchesPrHeadSha
+  ) {
+    return
+  }
+
+  throw new Error(
+    `Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
+      `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
+      `cache scope, and runner access. Fetching and executing a fork's code in that trusted ` +
+      `context commonly leads to "pwn request" vulnerabilities. To opt in, review the risks ` +
+      `at https://gh.io/securely-using-pull_request_target and set 'allow-unsafe-pr-checkout: true' ` +
+      `on the actions/checkout step.`
+  )
+}
+
+function pushIfSha(target: string[], value: unknown): void {
+  if (typeof value === 'string' && value.length > 0) {
+    target.push(value.toLowerCase())
+  }
+}

src/workflow-context-helper.ts

@@ -0,0 +1,30 @@
+import * as core from '@actions/core'
+import * as fs from 'fs'
+
+/**
+ * Gets the organization ID of the running workflow or undefined if the value cannot be loaded from the GITHUB_EVENT_PATH
+ */
+export async function getOrganizationId(): Promise<number | undefined> {
+  try {
+    const eventPath = process.env.GITHUB_EVENT_PATH
+    if (!eventPath) {
+      core.debug(`GITHUB_EVENT_PATH is not defined`)
+      return
+    }
+
+    const content = await fs.promises.readFile(eventPath, {encoding: 'utf8'})
+    const event = JSON.parse(content)
+    const id = event?.repository?.owner?.id
+    if (typeof id !== 'number') {
+      core.debug('Repository owner ID not found within GITHUB event info')
+      return
+    }
+
+    return id as number
+  } catch (err) {
+    core.debug(
+      `Unable to load organization ID from GITHUB_EVENT_PATH: ${(err as any)
+        .message || err}`
+    )
+  }
+}

tsconfig.json

@@ -10,7 +10,8 @@
     "declaration": true,
     "strict": true,
     "noImplicitAny": false,
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "skipLibCheck": true
   },
   "exclude": ["__test__", "lib", "node_modules"]
 }